What is diphtheria?

What is diphtheria?

Diphtheria is a contagious infection caused by a bacterium called Corynebacterium diphtheriae. The bacterium releases a toxin that causes a buildup of grey tissue in your throat, leading to problems with swallowing and breathing.

In warmer climates, someone with diphtheria might also develop skin sores that will not heal and may be covered with the grey tissue. This type of diphtheria (called cutaneous diphtheria) also happens sometimes in the U.S. when people live in crowded and unhealthy conditions.